Unless otherwise indicated herein, the materials described in this section are not prior art to the claims and are not admitted to be prior art by inclusion in this section.
A cellular wireless network may include a number of base stations that radiate to define wireless coverage areas, such as cells and cell sectors, in which mobile terminals such as cell phones, tablet computers, tracking devices, embedded wireless modules, and other wirelessly equipped communication devices, can operate. In turn, each base station may be coupled with network infrastructure including a network access server (NAS) that provides connectivity with a packet-switched network such as the Internet. With this arrangement, a mobile terminal within coverage of the network may engage in air interface communication with a base station and may thereby communicate via the base station and via the NAS with various entities on the packet-switched network.
When such a mobile terminal enters into coverage of the network, the mobile terminal may register with the network, and the network may work with the mobile terminal to establish a radio link layer connection between a base station and the mobile terminal and a data link layer connection between the NAS and the mobile terminal. Further, the NAS may provide the mobile terminal with an assignment of a network address on the packet-switched network. Outgoing packet-data may then flow from the mobile terminal over the radio link layer connection to the base station, from the base station to the NAS, and from the NAS onto the packet-switched network for routing to its destination. Similarly, incoming packet-data destined to the mobile terminal's assigned network address may arrive at the NAS and may then flow to the base station and over the radio link layer connection to the mobile terminal.
Furthermore, after a threshold period of time of no packet-data flowing over the radio-link layer connection, the network may automatically release the assigned radio link layer connection but maintain the data link layer connection with the NAS and the network address assignment for the mobile terminal, thereby putting the mobile terminal into a dormant mode. With the mobile terminal in the dormant mode, if the NAS receives incoming packet-data destined to the mobile terminal, the network may page the mobile terminal to cause the mobile terminal to work with the network to re-acquire a radio link layer connection over which to receive the packet-data, and the NAS may then send the packet-data to the mobile terminal as described above. Likewise, if a mobile terminal in the dormant mode seeks to transmit outgoing packet-data from its assigned network address, the mobile terminal may similarly work with the network to re-acquire a radio link layer connection, and the mobile terminal may then transmit the packet-data as described above.